Impact of monitoring blood volume in the BD BACTEC™ FX blood culture system: virtual volume versus actual volume

Diagn Microbiol Infect Dis. 2015 Feb;81(2):89-93. doi: 10.1016/j.diagmicrobio.2014.11.001. Epub 2014 Nov 7.

Abstract

The BACTEC™ FX (BD, USA) has been recently upgraded to measure virtual blood volume (VV) in batches of 25 PLUS Aerobic/F bottles. VVs were compared with manually measured actual volumes (AVs). The mean AV was larger in anaerobic bottles: 2.6±1.9mL in 2995 Aerobic/F bottles and 3.3±1.8mL in 3053 Lytic/10 Anaerobic/F bottles (P<0.001). The VV of Aerobic/F bottles was 2.4±1.4mL, and there was a significant correlation between the VVs and AVs of each department (P<0.001). The potential positivity in aerobic bottles increased 1.2-fold with a 1-mL increase in the AV (P<0.001). AV and VV were consistently less than adequate. Although the proportional effect of volume on positivity can be proven only with the AV, VVs are a reliable substitute for AVs to monitor the overall blood volumes and provide feedback to the individual departments or locations.

Keywords: Aerobic bottle; Anaerobic bottle; Blood culture; Blood volume; Monitoring.

MeSH terms

  • Adult
  • Bacteremia / diagnosis*
  • Bacteriological Techniques / methods*
  • Blood / microbiology*
  • Humans
  • Prospective Studies
  • Sensitivity and Specificity
  • Specimen Handling / methods*
  • United States